scholarly journals Closure to “Discussions of ‘The Dominant Unstable Wavelength and Minimum Heat Flux During Film Boiling on a Horizontal Cylinder’” (1964, ASME J. Heat Transfer, 86, p. 225)

1964 ◽  
Vol 86 (2) ◽  
pp. 225-226
Author(s):  
J. H. Lienhard ◽  
P. T. Y. Wong
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Horizontal Cylinder ◽  
Film Boiling ◽  
Minimum Heat

The Dominant Unstable Wavelength and Minimum Heat Flux During Film Boiling on a Horizontal Cylinder

1964 ◽  
Vol 86 (2) ◽  
pp. 220-225 ◽  
Author(s):  
J. H. Lienhard ◽  
P. T. Y. Wong
Keyword(s):  
Surface Tension ◽  
Heat Flux ◽  
Flat Plate ◽  
Transverse Direction ◽  
Horizontal Cylinder ◽  
Heat Fluxes ◽  
Taylor Instability ◽  
Film Boiling ◽  
Minimum Heat ◽  
Effect Of Surface

Predictions of the dominant unstable wavelength and the minimum heat flux during film boiling above a flat plate are found to be inapplicable in the case of boiling on small wires. New expressions are developed for the case of a horizontal cylinder, by accounting for the effect of surface tension in the transverse direction upon the Taylor instability of the interface. Original measurements of wavelengths and minimum heat fluxes on small wires are also provided. These data support the predictions.

scholarly journals Film boiling heat transfer and minimum-heat-flux(MHF)-point condition in subcooled pool boiling.

1987 ◽  
Vol 30 (266) ◽  
pp. 1274-1281 ◽  
Author(s):  
Shigefumi NISHIO ◽  
Mitsuhiro UEMURA ◽  
Kazutaka SAKAGUCHI
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Boiling Heat Transfer ◽  
Pool Boiling ◽  
Film Boiling ◽  
Point Condition ◽  
Minimum Heat

Film Boiling Incipience at the Departure From Natural Convection on Flat, Smooth Surfaces

1998 ◽  
Vol 120 (2) ◽  
pp. 402-409 ◽  
Author(s):  
J. Y. Chang ◽  
S. M. You ◽  
A. Haji-Sheikh
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Natural Convection ◽  
Smooth Surface ◽  
Boiling Curve ◽  
Film Boiling ◽  
Smooth Surfaces ◽  
Wall Superheat ◽  
Boiling Incipience ◽  
Minimum Heat

The present research is an experimental study of pool boiling nucleation behavior using flat, smooth surfaces immersed in saturated highly wetting liquids, FC-72 and FC-87. A flush-mounted, copper surface of 10 mm × 10 mm is used as a heat transfer surface, simulating a microelectronic chip surface. At the nucleation incipient points of higher wall superheats with steady increase of heat flux, vapor film blankets the smooth surface and remains on the surface. To predict this film boiling incipience phenomenon from the smooth surface, an incipience map is developed over the boiling curve. When the incipient heat flux is higher than the minimum heat flux (MHF) and the incipient wall superheat value is higher than the transition boiling curve value at the incipient heat flux, the transition from single-phase natural convection to film boiling is observed at the incipient point. To prevent film boiling incipience, a microporous coating is applied over the smooth surface, which decreases incipient wall superheat and increases minimum heat flux. The film boiling incipience should be avoided to take advantage of highly efficient nucleate boiling heat transfer for the cooling of high-heat-flux applications.

scholarly journals CHF Phenomena by Photographic Study of Boiling Behavior due to Transient Heat Inputs

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Jongdoc Park ◽  
Katsuya Fukuda ◽  
Qiusheng Liu
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
High Speed ◽  
Video Camera ◽  
Nucleate Boiling ◽  
Horizontal Cylinder ◽  
Heat Transfer Process ◽  
Film Boiling ◽  
Bubble Behavior ◽  
Camera System

The transient boiling heat transfer characteristics in a pool of water and highly wetting liquids such as ethanol and FC-72 due to an exponentially increasing heat input of various rates were investigated using the 1.0 mm diameter experimental heater shaped in a horizontal cylinder for wide ranges of pressure and subcooling. The trend of critical heat flux (CHF) values in relation to the periods was divided into three groups. The CHF belonging to the 1st group with a longer period occurs with a fully developed nucleate boiling (FDNB) heat transfer process. For the 2nd group with shorter periods, the direct transition to film boiling from non boiling occurs as an explosive boiling. The direct boiling transition at the CHF from non-boiling regime to film boiling occurred without a heat flux increase. It was confirmed that the initial boiling behavior is significantly affected by the property and the wettability of the liquid. The photographic observations on the vapor bubble behavior during transitions to film boiling were performed using a high-speed video camera system.

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